Fuels and Energy Technology Institute and Department of Chemical Engineering, Curtin University, Perth, Western Australia, 6102, Australia.
Australian Synchrotron, Clayton, Victoria, 3168, Australia.
Adv Mater. 2018 Mar;30(13):e1706287. doi: 10.1002/adma.201706287. Epub 2018 Feb 9.
Single-atom catalysts (SACs) are the smallest entities for catalytic reactions with projected high atomic efficiency, superior activity, and selectivity; however, practical applications of SACs suffer from a very low metal loading of 1-2 wt%. Here, a class of SACs based on atomically dispersed transition metals on nitrogen-doped carbon nanotubes (MSA-N-CNTs, where M = Ni, Co, NiCo, CoFe, and NiPt) is synthesized with an extraordinarily high metal loading, e.g., 20 wt% in the case of NiSA-N-CNTs, using a new multistep pyrolysis process. Among these materials, NiSA-N-CNTs show an excellent selectivity and activity for the electrochemical reduction of CO to CO, achieving a turnover frequency (TOF) of 11.7 s at -0.55 V (vs reversible hydrogen electrode (RHE)), two orders of magnitude higher than Ni nanoparticles supported on CNTs.
单原子催化剂 (SACs) 是催化反应的最小实体，具有预计的高原子效率、优异的活性和选择性；然而，SAC 的实际应用受到金属负载量非常低（1-2wt%）的限制。在这里，通过一种新的多步热解工艺，合成了一类基于氮掺杂碳纳米管上原子分散过渡金属的 SAC（MSA-N-CNTs，其中 M = Ni、Co、NiCo、CoFe 和 NiPt），具有极高的金属负载量，例如 NiSA-N-CNTs 的负载量为 20wt%。在这些材料中，NiSA-N-CNTs 对 CO 电化学还原为 CO 表现出优异的选择性和活性，在 -0.55 V（相对于可逆氢电极 (RHE)）下的周转频率 (TOF) 达到 11.7 s-1，比负载在 CNTs 上的 Ni 纳米颗粒高两个数量级。
